JPH08323790A - Apparatus and method for molding two-color laminated molded product - Google Patents

Abstract

PURPOSE: To produce a two-color laminated molded product excellent in appearance design effect by setting the temp. of a molten resin in sufficient consideration of the flowability thereof and preventing the peel of the foam layer on the rear surface of a skin material. CONSTITUTION: A pair of cooling water passages 40, 50 separately cooling the skin material molding surface 61 and resin material molding surface 62 of an upper mold 20 or lower mold 30 and a temp. control means 90 separately controlling the temps. of cooling water of the cooling water passages 40, 50 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus and a molding method for a multi-layered molded product composed of a skin material and a thermoplastic resin, and in particular to a skin material and a thermoplastic resin in which only a predetermined portion is covered with the skin material. The present invention relates to a molding device and a molding method for a color laminated molded product.

Here, the two-color laminated molded product means a molded product in which a part of the molded product is covered with a skin material, but the other parts have a resin core material exposed.

[0003]

2. Description of the Related Art A two-color laminated molded product of a skin material and a thermoplastic resin, in which only a predetermined portion is covered with a skin material as described above, is used for interior parts such as door trims and rear side trims of automobiles. In the production of such a two-color laminated molded product, a thermoplastic resin is previously molded into a resin core material by injection molding or the like, and a skin material having a predetermined shape is attached to the resin core material by using an adhesive or the like. Alternatively, there is a method in which a part in which a skin material is pasted on a hardboard is manufactured in advance, and this part is attached to the resin core material by using screws or the like. It takes time and labor, and is a factor of cost increase.

Therefore, in order to improve the production of such a two-color laminated molded article, for example, Japanese Patent Laid-Open No. 64-26414.
The one described in the publication is proposed. According to this, when a skin material and a molten resin are supplied between the unmolded upper and lower molds for molding, the upper and lower molds are closed, and a predetermined shape is produced when a two-color molded product composed of the skin material and the thermoplastic resin is manufactured. The cut skin material is placed at a predetermined position on the upper or lower mold, and the welding resin is supplied to the substantially central portion of the back surface side of the skin material, so that the skin material is covered with only the predetermined portion. It is to obtain a two-color laminated molded product with a thermoplastic resin.

The production of such a two-color laminated product is carried out in the following steps (see FIG. 5).

The skin material cut into a predetermined size is placed on a predetermined portion of the molding surface of the upper mold 7 with the surface side 3 facing upward.

Next, an elevating mechanism (not shown) of the mold clamping device is operated to lower the upper mold 7 so that the clearance of the cavity surface formed by the upper mold 7 and the lower mold 9 is larger than the product thickness. Stop once at the position (state shown). At this stop position, the molten resin 4 is supplied to the back surface side of the skin material 3 by a molten resin supply device (not shown) such as an injection molding machine through a resin passage (not shown) provided in the lower mold 7. To do.

Next, when the elevating mechanism is actuated again to lower the upper die 7 to press the skin material 3 toward the lower die 9, the molten resin 4 flows and expands between the die cavities, and the skin The material 3 and the thermoplastic resin are integrated to complete the shaping. As a result, a two-color laminated molded product, a part of which is covered with the skin material 3, is completed.

Then, the molten resin 4 is flow-expanded and molded between the mold cavities as the upper mold 7 descends with respect to the lower mold 9 in accordance with the shaping process. Therefore, it spreads evenly throughout the mold cavity,
In order to be molded into a predetermined shape, a molten resin having a sufficiently high resin temperature is usually used to enhance the fluidity in the mold cavity.

On the other hand, in the case of molding by the above method, the portion contacted with the mold before the supplied molten resin is pressurized,
The heat is absorbed by the mold surface, and the temperature of the molten resin decreases, so there are problems such as significantly less gloss and smaller wrinkles than other parts after molding. In order to solve the problem, a measure was taken to raise the mold temperature sufficiently. However, this method has a problem that the cooling time required until the product is taken out becomes long, the production cycle becomes long, and the product cost becomes high, especially when the molded product has a large wall thickness. A device provided with a cooling device is proposed (for example, JP-A-60-24).
8326 publication).

[0011]

However, in the production of the above-mentioned two-color laminated molded article, it should be noted that the skin material is placed in the mold in advance and then the molten resin is supplied to mold it. That is the point.

That is, this skin material is usually formed of a surface layer made of a vinyl chloride sheet and a foam layer made of polypropylene foam or the like lined on the back surface thereof.
When molding the two-color laminated molded product, when this skin material is placed on the mold, the surface layer contacts the mold molding surface, and conversely the foam layer appears on the cavity side and melts at high temperature. It will be directly exposed to the resin.

As a result, the foamed layer may be partly peeled off due to high-speed flow of molten resin or high temperature. The peeled foamed layer mixes with the molten resin and flows to other parts, so that the resin core material It is possible that the surface layer is exposed and causes a poor appearance, or that the thin layer of the foam layer exists on the back surface of the skin material from which the foam layer has peeled off, causing avatars (small dents) and bulges on the surface. .

In order to solve this point, a measure of lowering the temperature of the molten resin can be considered. However, in this measure, the fluidity of the molten resin is deteriorated, and the flow spreads evenly throughout the mold cavity. It is conceivable that such a phenomenon may occur that the external appearance is not formed into a predetermined shape, a defective appearance such as a short shot occurs, and the external appearance is deteriorated.

In view of the above circumstances, the present invention takes into consideration the fluidity of the molten resin temperature, and also prevents peeling of the foamed layer on the back surface of the skin material, thereby providing a two-color resin having an excellent appearance design. It is an object of the present invention to provide a manufacturing apparatus and a molding method for a laminated molded product.

[0016]

The first invention for achieving the above object is to provide a molding apparatus for a two-color laminated molded article,
A resin core material formed by molding a molten resin into a desired shape in a cavity formed by an upper mold and a lower mold for mold press molding, and a part of the surface of the resin core material during mold press molding of this resin core material. In a molding apparatus for a laminated molded body composed of a skin material to be coated on, at least a pair of cooling for separately cooling the skin material side molding surface and the other molding surface in the upper mold or the lower mold. It has a water passage and a temperature control means for separately controlling the cooling water temperature of these cooling water passages.

The second invention is, as a method of molding a two-color laminated molded article, a resin core obtained by molding a molten resin into a required shape in a cavity formed by an upper mold and a lower mold for mold press molding. In a molding method of a laminated molded body composed of a material and a skin material covering a part of the surface of the resin core material at the time of mold press molding of the resin core material. Alternatively, the surface of the lower mold on the skin material side and the other molding surface are cooled with cooling water having different temperatures.

The third invention is, as a molding device or molding method for a two-color laminated molded article, the cooling water temperature for cooling the molding material side molding surface of the upper mold or the lower mold, It is characterized in that the temperature is set lower than the cooling water temperature on the molding surface.

[0019]

With this structure, after the upper and lower molds are clamped, the molding surface of the upper mold or the lower mold is cooled at a low temperature to prevent the back foam layer of the skin from peeling off. The molding surfaces other than the molding surface are kept at a high temperature to sufficiently enhance the fluidity of the molten resin.

[0020]

EXAMPLE A two-color laminated molded article manufactured by the molding apparatus or molding method of the present invention will be described below with reference to FIG.
And a door trim as an automobile interior member as shown in FIG.

Therefore, FIG. 1 is a perspective view of the door trim, and FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1. The door trim 10 is a resin core which is a thermoplastic resin molded into a desired shape. The material 11 and a skin material 12 adhered to and integrated with a part of the surface of the resin core material 11 are roughly constituted. The resin core material 11 is made of polypropylene resin mixed with a filler such as talc. The skin material 12 is formed of a top layer 12a made of a vinyl chloride sheet and a foam layer 12b made of polypropylene foam or the like lined on the back surface thereof. It will be integrally attached to a part of the surface side of 11. Furthermore, a wood grain groove 14 is formed in the resin core material 11 along a parting line 13 along the underline of the skin material 12, and the ends of the skin material 12 are grained in the wood grain groove 14 to form the wood core material 11. Is a two-color molded product including an upper portion A coated with the skin material 12 and a lower portion B not coated. Further, in addition to the wood-grooving groove 14 provided in the parting line 13, a wood-grooving groove 15 is formed, and the end of the middle joint decorative sheet 12d located in the central portion of the skin material 12 and the skin material 12 is wood-grained. ing.

On the other hand, the door trim 10 as described above is molded by a molding apparatus as shown in FIGS. 3 and 4.

That is, FIG. 3 is a plan view of a molding apparatus showing an embodiment of the present invention, and FIG. 4 is a vertical sectional view taken along line IV-IV of FIG.

This molding apparatus comprises an upper mold 20 for molding, in which a skin material 12 preliminarily molded by another means such as a vacuum molding mold before the resin core 11 is molded is set by vacuum suction, and a resin. It comprises a lower die 30 for mold press molding to which the molten resin M, which is the material of the core material 11, is distributed and supplied.

Cooling water passages 40 and 50 are provided inside the molding surfaces of the upper and lower molds 20 and / or 30. These cooling water passages 40 and 50 respectively form the molding die cavity 60 of the door trim 11 from the grained groove 14 to the upper surface A on the skin material side.
1 and the other resin core material plain side molding surface 62 corresponding to the lower part B, and the cooling passage 40 is cooled to the skin material side molding surface 61 side and the resin core material plain side molding surface 62 side is cooled. Water passage 50
Is arranged.

The cooling water passages 40 and 50 are provided.
The inlets 41 and 51 communicate with the reservoir tank 80 through the cooling water supply pipes 71 and 72, and the outlets 42 and 51
52 communicates with the reservoir tank 80 through cooling water return pipes 73 and 74.

The cooling pipes 71 and 72 are connected to the cooling water passages 40 and 5 while reaching the reservoir tank 81.
Temperature control means 90, pump 8 from the inlet 41, 51 side of 0
2 are sequentially arranged.

The temperature control means 90 includes cooling water passages 40 and 5
The temperature of the cooling water supplied by the pump 82 from the reservoir tank 81 to 0 is independently controlled.

A molding method for molding a two-color laminated molded product using the above-described molding device will be described below.
In carrying out this method, the top layer 12 of the skin material 12
A PVC sheet having a thickness of 0.6 mm was used for a, and a polyethylene foam (thickness: 3.0 mm) with 15 times expansion was used as the foam layer 12b. Further, as the molten resin M, polypropylene resin having a melt index value of 100 or more is used in an amount of 10 parts by weight or less, preferably 5 parts by weight or less based on the total weight.
A mixture containing -10 parts by weight of talc was used.

First, in a state where the upper and lower molds 20 and 30 for mold press molding are opened, the skin material 12 preformed into a required shape is placed on the molding surface of the upper mold 20 with the top layer 12a facing upward. set.

At this time, the skin material 12 is held in close contact with the skin material 12 of the upper die 20 at an appropriate position by vacuum suction or the like.

Thereafter, the upper mold 20 having the skin material 12 set thereon.
Is moved down by a predetermined stroke, and when the clearance between the upper and lower molds 20, 30 reaches 10 to 50 mm, the upper mold 20 is temporarily stopped (state in FIG. 4).

Then, a molten resin supply device 82 such as an injection molding machine distributes and supplies the molten resin M to predetermined positions on the die surface 30. The molten resin M is supplied only to the back surface side of the skin material 12 by the molten resin supply device 82,
Flow marks and the like are not exposed on the surface of the molding side 62 on the plain side of the resin core material.

Thereafter, the upper die 20 is further lowered to the bottom dead center where the core material is set to have a predetermined thickness, and the resin core material 11 is molded into a required shape, and at the same time, the resin core material 11 is formed. The skin material 12 is integrally attached to a part of the surface side of the, and the molding step is completed.

In this molding step, the skin material side molding surface 61 side of the molding die cavity 60 and the resin core material plain side molding surface 62 side are the cooling passage 40 and the cooling passage 50.
In addition, the cooling water is separately cooled by the cooling water whose temperature is controlled by the temperature control means 90.

Then, the skin material of the present invention is optimally used in, for example, a door trim for automobiles, and as a result of earnest study from the viewpoint of satisfying both the commercial property and the cost, the results are shown in Table 1. The skin material was judged to be optimal.

[0037]

[Table 1] That is, when the thickness of the top layer 12a of the skin material 12 is selected from the viewpoint of cost, it is better that the thickness is thin. However, in the molding, the skin is cut and the resin core material 11 is removed at a portion having a large expansion rate. A phenomenon in which the molten resin M to be formed leaks from the breaks to the surface, which deteriorates the moldability. In addition, from the viewpoint of decoration, the top layer 12a is provided with a "texture pattern", but this "texture pattern" may become shallow, or it may not flow into a texture pattern, leaving a problem in commercialability. . On the other hand, when the plate thickness of the top layer 12a is increased, the normal formation of a portion having a large expansion rate is good, and a good "texture pattern" is formed, but the cost becomes expensive. Therefore, from the aspects of cost and commercialability, in the above-mentioned embodiment, the plate thickness of the top layer 12a is optimum as shown in Table 1 to be 0.5 to 0.6 mm.

The thickness of the foamed layer is preferably thin if it is selected from the viewpoint of cost. However, if it is too thin, it is stiff and lacks cushioning, resulting in poor feel, and problems in molding such as avatars. Came out, and there was a problem in terms of merchandise. Further, if the foam layer 12b is made thicker, it becomes softer and the cushioning property is enhanced, and the heat insulating effect is enhanced, so that the occurrence of avatars and the like is reduced and the commercial property is enhanced, but it is expensive in terms of cost. It becomes a thing. Therefore, in the above embodiment, as shown in Table 1, the thickness of the foam layer 12b is
The one with 3 to 5 mm was selected. According to this, the skin material 12
When simultaneous molding is performed simultaneously with molding of the resin core material 11,
When the foam layer 12b having a thickness of 3 to 5 mm was used, even if a part of the foam layer 12b was melted by heat or the like, the remaining thickness was at least 1.5 mm, and the cushioning property was not deteriorated. Further, in the case of preliminary shaping in which the skin material 12 is shaped in advance, the resin core material 11
At the time of forming, when the skin material 12 is sucked into the upper mold and vacuum formed, the residual pressure after vacuum forming is 2 mm in the part with a large expansion rate.
The molten resin M that forms the resin core material 11 in the foam layer 12b of the preliminarily shaped skin material 12
Had good flowability and did not cause peeling or the like.

Next, regarding the foaming rate of the foaming layer 12b, if this is selected from the viewpoint of cost, the higher the foaming rate, the better, but if it is too high, the resin core material 11 has a feeling of bottoming.
Moreover, the peeling phenomenon is likely to occur, and avatars and the like are often generated. On the other hand, if the foaming rate is lowered, avatars and the like are less likely to come out, but on the other hand, it is so hard that it lacks cushioning properties and is disadvantageous in terms of cost. Therefore,
As shown in Table 1, the foaming rate of the foaming layer 12b is 15 to 2
A 5-fold foam was selected. Then, in this selection, various foaming rates of the foaming layer 12b were examined from the viewpoint of the avatar generation rate. However, when the foaming rate is low, the cells constituting the foaming layer 12b are appropriately small, and the cells per unit area are small. The cells are made of many walls and are rich in strength. When the foaming rate is increased, the strength is deteriorated, so that avatars are often generated. The generation of avatars is caused by the destruction of cells, but if the expansion ratio is small, the cells become small, and even if they are crushed at the same number as the large cells in the foam layer having a high expansion rate, they are crushed. , The foam layer 12b
The amount of dents on the surface of the will be small. In the course of such an examination, the plate thickness 5 of the wood grain groove forming portion of the resin core material 11 is made thicker than the general plate thickness 6 of the other portions, and in view of commercialability and cost. 1
As a result of selecting the foaming ratio shown in (3), it has become possible to provide a two-color laminated molded article which is most suitable as an interior material such as an automobile door trim.

[0040]

As described above, in the present invention, after the upper and lower molds are clamped, the molding material side molding surface of the upper mold or the lower mold is cooled at a low temperature and the back surface of the skin material is foamed. Prevents peeling of layers and prevents avatars and swelling, and the molding surfaces other than the molding surface on the skin material side are kept at a high temperature to sufficiently enhance the fluidity of the molten resin and to always maintain a predetermined shape. Thus, the effect of improving the external appearance designability is achieved without causing the appearance failure due to the molding.

[Brief description of drawings]

FIG. 1 is a front perspective view of an automobile door trim formed according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a plan view showing a molding apparatus for a two-color laminated molded product according to an embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a cross-sectional view of a conventional molding apparatus for a two-color laminated molded product corresponding to FIG.

[Explanation of symbols]

 40 Cooling Water Passage 50 Cooling Water Passage 60 Mold Cavity 61 Molding Surface for Skin Material 62 Molding Surface for Resin Core Material 90 Temperature Control Means

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Claims (4)

[Claims] 1. A resin core material formed by molding a molten resin into a desired shape in a cavity formed by an upper mold and a lower mold for mold press molding, and a resin core material at the time of mold press molding of this resin core material. In a molding device for a laminated molded body composed of a skin material covering a part of the surface of the above, the skin material side molding surface of the upper mold or the lower mold and the other molding surface are separately cooled. A molding device for a two-color laminated molded article, comprising at least a pair of cooling water passages, and temperature control means for separately controlling the cooling water temperature of these cooling water passages. 2. The temperature control means sets and controls the cooling water temperature for cooling the surface side molding surface of the upper mold or the lower mold lower than the cooling water temperature of the other molding surfaces. 2. The molding apparatus for a two-color laminated molded product according to claim 1. 3. A resin core material formed by molding a molten resin into a required shape in a cavity formed by an upper mold and a lower mold for mold press molding, and a resin core material during mold press molding of this resin core material. In the method for molding a laminated molded body composed of a skin material that covers a part of the surface of, at the time of molding,
A two-color laminated molded article characterized by cooling the skin material side molding surface and the other molding surface in the upper mold or the lower mold at the time of molding the laminated body with cooling water of respectively different temperatures. Molding method. 4. The temperature of the cooling water for cooling the skin material side molding surface of the upper mold or the lower mold is set to be lower than the cooling water temperature of the other molding surfaces. A method for molding the two-color laminated molded article described.